Ultrasonic Automotive Wiper System Design

The ultrasonic car wiper would be a trend in the future of car windshield, it was a kind of application in ultrasonic car wiper, for now, it was also the development trend of breakthrough in scientific research above the world. The ultrasonic was used widely in kinds of scientific field, for example in the medicine,test,clean and so on. The system of ultrasonic car wiper mostly used the mechanical vibration characteristics of ultrasonic to produce the vibration by the transitive ultrasonic in the windshield, then it would clean up the any impurity substance which would and already have drift down on the windshield, for example the rain above the windshield, insect and so on. The characters of ultrasonic car wiper were overcome the shortcoming to make it possible that it became more efficient in cleaning up any impurity substance to make the driver’s sight line more clear, and made the streamlining more great and reduced resistance.Ultrasonic excitation electric system was the most important part of ultrasonic car wiper system, through the excitation, energy converter produced crooked ultrasonic in the windshield to clean the window. Incentive system includes a double output DC-DC positive and negative voltage conversion circuit, DDS sine wave generator and class D power amplifier circuit.Ultrasonic transmission equipment was applied power by the global high frequency electronics, and also the battery voltage used be the input voltage as double export DC-DC, the positive and negative voltage was partly as the triangular wave generating circuit and power voltage of D power amplifier, it took the wave produced by the DDS sine wave generator and would amplify the sine wave to impel ultrasonic transducer, at last, the ultrasonic signals would be export through the electric acoustic signal conversion transmitting transducer.Put a number of transmitting transducer mounted on the side of the windscreen, on the other side of the corresponding with the same number of receiving transducer. One side of the windscreen transmitting transducer through the incentive system of incentives to emit ultrasonic, the ultrasonic propagation along the windscreen to the other side of the receiving transducer and receiving transducer converts the received ultrasonic signals to the receiving circuit, after receiving system of general electric consumption of acoustic energy absorbing circuit processing, or after recovery of acoustic energy absorbing circuit electricity charging to the battery, save the energy.This thesis made the research in a king of piezoelectric rectangular thin plate transducer, which made it possible to apply in the ultrasonic car wiper system, the thickness of piezoelectric rectangular thin plate transducer was with polarization direction, the transducer had both sides, on one side was positive electrode, the other was negative electrode, it formed polarization direction in thickness. This thesis made the design plan for the ultrasonic car wiper system and analyzed how to realize in the specific circuit, it mostly conclude all parts circuit of ultrasonic car wiper system, the absorbing circuit of general and recycling sound wave energy absorbing circuit, then article tested various parts of the circuit at last.